A plasma cluster tool is made up of a plurality of modules (i.e., processing module, transfer module, etc.). Each of these modules is made up of a plurality of subsystems (i.e., RF match, gas box, TCP match, bias match, etc.). For ease of discussion, the term “component” will be used to refer to an atomic or a multi-part assembly in a plasma cluster tool. Thus, a component may be as simple as a gas line or may be as complex as the entire process module. A multi-part component (such as a process module) may be formed from other multi-part components (such as a vacuum system, a gas system, a power supply system, etc), which may in turn be formed from other multi-part or atomic components.
Generally, the various components of a plasma cluster tool may be manufactured by more than one party. For example, a manufacturer of plasma cluster tool, such as Lam Research Corporation of Fremont, Calif., typically utilizes components from a member of third-party suppliers in the manufacturing of a plasma cluster tool. In fact, such practice is standard in the semiconductor processing equipment field since it permits companies to focus on their strengths while delegating tasks outside of their fields of interest or expertise to other companies.
Before a plasma cluster tool is sent to a customer by a manufacturer, a multitude of quality control tests are performed on the plasma cluster tool and its various components. The tests may be performed by the manufacturer and/or by a third-party. Currently, a standard testing framework does not exist. Tests performed internally allow the manufacturer some control on the testing methodology. However, tests that have been outsourced to a third-party allow the manufacturer limited or no control over the tests that are performed.
To aid in testing components, test fixtures may be available. As discussed herein, a test fixture is hardware with a software interface that allows a component to be tested in a simulated processing environment. For example, a test fixture is created to test an AC/DC box. The test fixture is able to test the wiring connection, the power components, etc. The test fixture is also able to log the data and stores the data on the test fixture.
Tests that are performed using test fixtures created by the manufacturer allow the manufacturer some control on the testing methodology that may be used. If the tests are performed internally, the manufacturer may have access to the electronic version of the data that are gathered, thus enabling the manufacturer the ability to manipulate the data for analysis. However, for tests that are performed off-site by a third-party, the manufacturer generally has limited access to the data since the data is usually provided to the manufacturer in a paper or image format. As a result, the manufacturer may have difficulties manipulating the data for analysis.
In some situations, test fixtures may be created by third-party suppliers. In these situations, the third-party suppliers may have incorporated their own testing methodology and control logic (which may differ significantly from the production environment of the plasma cluster tool) into the test fixtures. Consequently, the manufacturer is dependent upon testers using test fixtures created by third-party suppliers to perform good tests and collect relevant data on the components.
In some instances, a test fixture may not exist for a component. Thus, any testing that may be performed on the component has to be performed manually using paper procedures. With paper procedures, the quality of the test is dependent upon a tester's skills and discretion. Furthermore, the procedures are subjected to interpretation by the tester. Also, the tester may not always perform all steps completely. In some cases, a tester may fabricate data. Thus, test results may be inconsistent and may lack integrity.
Since the testing methodology may vary, the data that is gathered may differ in substance and quality depending upon the testing methodology and the tester. Further, the reports that are produced from the testing may vary by format and substance. If the testing is performed internally, the manufacturer may have access to the electronic data and may have some ability to manipulate the data and to produce reports that are usable by the manufacturer. However, if tests are performed off-site by a third-party, an electronic copy of the data is usually not available. Instead, the third-party usually provides a paper or an image copy of the data and the manufacture is unable to manipulate the data. As a result, traceability is almost impossible when a problem arises.
To facilitate discussion, FIG. 1A shows an example of a plasma cluster tool with a process module 102 and a transfer module 111. Within process module 102 are components 106 and 108 (i.e., Gas Box and RF Match. Attached to process module 102 is a test fixture 112 (i.e., LamWorks), which enables the entire process module 102 to be tested. Additional test fixtures (i.e., LamWorks based test fixture 104 and Nyker Labview test fixture 110) are attached to components 106 and 108.
As discussed, test fixtures are not always available. In this example, a test fixture is not available for transfer module 111. Thus, tests that may be performed on transfer module 111 have to be performed using paper procedures and the data has to be gathered manually by the tester.
FIG. 1B shows a chart of the components in FIG. 1A and the testing architecture associated with these components. For process module 102, a test fixture (i.e., LamWorks) produced internally by the manufacturer is attached. The data collected by the test fixture is logged onto a SQL database. The reporting or access to the report is limited to an internal intranet or a paper printout. Also, even though the test fixture is internally produced, the control system is different from that of the actual production environment. Thus, possibility of a discrepancy between the production and test environments will most likely exist.
Likewise, the test fixture (i.e., LamWorks) attached to component 106 (i.e., RF Match) is internally created but has been sent off-site to a third-party to test the component. Thus, the manufacture is most likely to receive a paper printout only. Further, the control logic for the test fixture is not the actual production environment.
In regard to component 108 (i.e., Gas Box), test fixture (i.e., Nyker using LabView) may be created by a third-party. The data collected by the test fixture is also store onto a SQL database. However, since it is not an internal test fixture, the manufacturer is usually limited to paper printout only. As with the previous test fixtures, the control logic may also be different than that of the production environment.
In some cases, a component, such as transfer module 111, may not have a test fixture associated with the component. In situations where there are no test fixtures, the tester has to rely on paper procedures to perform any type of test on the component. The test methodology for this situation is usually dependent upon the skill and knowledge of the tester. Further, the data collected is dependent upon the discretion of the tester. For example, the tester may choose not to perform a thorough test (such as skipping some of the steps) or the tester may choose to bypass the test and fabricate the data. Generally, the data collected is stored directly on paper and the information is scanned into the system. Like the other scenarios, the control logic may differ from the one in the production environment.
As can be appreciated from the above-discussion, the control logic for testing usually does not resemble that of the production environment. Further, each test fixture may have its own control logic. As a result, the test environment may not be able to replicate what may happen in the production environment. For example, it is not unusual for changes to be occurring in the control system as a plasma cluster tool is being manufactured. However, the changes may not always be propagated to all the testers. As a result, the testers may not have all the data to create an environment that resembles the production environment. Further, there may have been changes in the various components, but the manufacturer may not have been informed to accommodate the changes. As a result, changes may not be noticeable until the plasma cluster tool is in the field.
The discussion above illustrates several problems with the current method of testing a plasma cluster tool and its components. First, the lack of testing standards, which may result in a wide range of testing methodology, inhibits manufacturers of cluster tool from being able to provide assurance to their customers that quality tests have been performed on all the components. Second, control logic which is different from the production control logic and which may vary in each test fixture may result in test results which may not capture what will happen in a real production environment. Third, the quality of the data collected may range depending upon the test fixture used and the tester performing the test. Fourth, data reporting lacks consistency. For example, some reports may be electronically produced while other may be in paper format. Finally, since a tester is usually limited to the component he/she is testing and the control logic does not represent a production environment, an integrated system test is not possible.